Procedures relying on unsupervised self-directed compliance of many individuals may be vulnerable to noncompliance, particularly where such noncompliance is not easily detectable after the fact. For example, hand hygiene procedures in hospitals and other healthcare settings, intended to prevent the spread of bacteria, viruses, and other disease-causing microorganisms, are often vulnerable to non-compliance. Typical hand hygiene procedures include conventional soap and water hand washing, and the use of antibacterial fluids, such as gels or foams, which has the advantage of not requiring rinsing of the hands. These procedures, while effective, are not easily and/or cost effectively verified after the fact.